Concentric suction and delivery valve for high pressure compressors and pumps



United States Patent [72] Inventor Anton Leitgeb Aesoh, Switzerland [21]Appl. No. 708,291 [22] Filed Feb. 26, 1968 [45] Patented Sept.1,l970[73] Assignee Maschinenfabrik Burckhardt AG Basel, Switzerland a Swisscompany [54] CONCENTRIC SUCTION AND DELIVERY VALVE FOR HIGH PRESSURECOMPRESSORS AND PUMPS 7 Claims, 3 Drawing Figs.

[52] U.S. Cl l37/5l2.3,

137/516.l3, 137/516.15; 230/231 [51] Int. Cl ..F16k 15/08, F04b 39/ 10[50] Field ofSearch 137/102, 516.1 l,516.l3,5l6.l5,512.3; 230/230, 231;251/282 [56] References Cited UNITED STATES PATENTS RE.25,899 11/1965Waibel l37/5l6.15X

Primary Exan1inerWilliam F. ODea Assistant Examiner-David J. Zobkiw Attorney- Wenderoth. Lind and Ponack ABSTRACT: A concentric suction anddelivery valve for high pressure compressors and pumps wherein a valvebody in a housing has oblique suction channels and a central deliverychannel. A suction valve lift-limiting member has an obturating membercooperating with the suction channels. A delivery valve seat is providedin the housing with an obturating member cooperating with the deliveryvalve seat. An intermediate ring is located between the valve body andthe delivery valve seat having a through bore of a form for high flowefficiency receiving the lift-limiting member. There is a delivery valvelift-limiting member. The valve body with the intermediate ring, thesuction valve lift-limiting member, the delivery valve seat and thedelivery valve lift-limiting member form a unit which can be inserted inand removed from the 2,703,217 3/1955 Ashton etal... 251/282 housing.The unit on its external surface is exposed to the ac- 3,106,169 10/1963Prosser et al. 230/231X tion ofthe delivery pressure at least in thezone corresponding 3,180,277 4/1965 Thresher 230/231X to the regionofoutflow ofthe suction channels.

0 l4 24 9 R Q k\ v CONCENTRIC SUCTION AND DELIVERY VALVE FOR HIGHPRESSURE COMPRESSORS ANDPUMPS A concentric suction and delivery valvefor high pressure compressors and pumps has been proposed in which thereare no steps and projections on the valve body which would give rise tostress concentrations through changes in cross section, and which at thesame time enables rapid mounting and dismounting in the high pressurecylinder.

According to that proposal, oblique suction channels and a centraldelivery channel are provided in the valve body of the concentricsuction and delivery valve, the valve body being combined with alift-limiting member to form a unit.

Atthe same time an element, e.g. a central tube is set in the bore inthe valve body forming the central delivery channel, the flow bore inwhich element has a form permitting efficient flow, the elementunitingthe valve body with the complete suction valve and the lift'limiting member thereof into a common'mountable and removable unit.

Any stress-raising changes of cross section in the parts of the valvebody exposed to alternating pressures are to a great extentavoided inthe concentric suction and delivery valves.

constructed in this manner. Further after releasing a cover or a closingscrew provided on the cylinder head the valve can be mounted in orremoved from the compressor or pump in a very short time without anyfurther dismounting operations.

An object of the present invention is to improve the concentric suctionand delivery valve for high pressure compressors and pumps according tothe above mentioned proposal, that easier assembly results from asimplified construction and possible dangers attaching to the priorvalve, e.g. through fracture of the central tube, are eliminated. Theconcentric suction and delivery valve according to the present'inventionis characterised in that an intermediate ring for accommodating asuction valve lift-limiting member having'a through bore of a form forhigh flow efficiency, is incorporated between the valve body and thedelivery valve seat, and that the valve body with the intermediate ringwith inset suction valve lift-limiting member, and the delivery valveseat together with the delivery valve lift-limiting member are builttogether into a unit which as a whole can be inserted in and removedfrom the valve housing, which unit on its external surface is exposed tothe action of the delivery pressure at least in the zone correspondingto the region of outflow of the suctionchannels.

Examples of the invention are illustrated in the accompanying drawing,wherein:

FIG. I shows a cross-section of the concentric suction and a deliveryvalve;

FIG. 2 is a partial view indicating a modified arrangement of -a'packingring; and

FIG.3 is a partial cross-sectional view showing another arrangement ofapacking ring.

' According to FIG. I the concentric suction and delivery valve is setinto a valve housing I having a cylindrical bore 2. The valve housing Ihaving a suction duct s and a delivery ductzr can he formed by thecylinder head ofa high pressure compressor or a high pressure pump. Thevalve body marked 3 on the left hand side is provided with suctionchannels 4 extending from its periphery, which run obliquely to a flat,conical'ordomed suction valve seating surface of the suction valve withwhich co-operates an annular obturating member 5, and are arrangedsurrounding a central bore 6 which serves for the through flow of themedium during the suction and delivery strokes. In the region of theentries to the oblique channels 4 an annular chamber 7 is providedbetween the channels and the housing 1 for the inflow ofthe medium. Thecentral bore 6 in the valve body 3 leads through a central bore 10 in asuction valve lift-limiting member 9 and a central bore 11 in a deliveryvalveseat 12 to the obturating member 13 of the delivery valve, thechamber of which is connected through bores I4 with the pressure chamber15 out of which the medium brought under pressure can flow away. Toachieve efficient flow conditions, the entry openings to the centralbores are well rounded.

In the arrangement illustrated during the suction stroke the medium tobe compressed flows under the suction pressure in the direction of thearrow through the annular chamber. 7 into the oblique bores 4 and theobturating member 5 of the suction valve opens against theforce of thespring 5a. The obturating member 13 of the delivery valve is held closedduring suction by the delivery pressure acting on it. During thedelivery stroke the medium drawn in is compressed by a piston (notshown) working in a bore 27, the suction valve obturating member 5 beingclosed by the. pressure acting through a bore 5b and the delivery valveobturating member 13 being opened by the pressure acting directly on thelatter.

An annular packing 16 of known kind is mounted on the left hand part ofthe valve body 3 at the inner end of the bore 18 in the housing 1,between the chamber 15 which is under delivery pressure and the chamber7 which is under suction pressure.

Between the valve body 3 and the delivery valve seat 12 is anintermediate ring 8 which has a smooth bore 17. The liftlimiting member9 for limiting the lift of the annular obturating member 5 is set in thebore 17.

So that the changes of form of the ring 8 as a result of the constantcompression pressure acting on the outside cylindrical surface of thering 8 and the suction and compression pressures acting alternatelyinside the bore 17, which changes can give rise to damaging frictioncorrosion on the abutment surfaces which can serve at the same time asseating surfaces, may be reduced, the ring 8 is made of a material whichhas a substantial higher modulus of elasticity and compressive strengththan the material of the adjoining valve body 3and delivery seat 12. Thechanges of form of the ring 8 under the pressure action are reduced bythe higher modulus of elasticity, and by corresponding choice of theinternal and external diameter of the ring, the changes of form can beso related to those of the adjacent abutment surfaces of the valve body3. and the delivery valve seat 12 that the relative movements under theinternal and external pressure actions are reduced to a minimum at theabutment surfaces and thus the danger of harmful friction corrosion isreduced to a considerable extent.

So that the harmful effect of alternating stresses in the range oftension in the region of the oblique bores 4 arranged surrounding thecentral bore 6 in the valve body 3, which stresses increase as the bores4 run nearer to the seating surfaces 19 for the annular suction valveobturating member 5 may be substantially reduced, the outer cylindricalsurfaces of the valve body 3 is exposed to the constant deliverypressure over a short portion din the region of the zone in which theoblique bores 4 lie in the immediate neighbourhood of the outlet fromthe central bore 6. Thereby the stresses in the valve body 3 produced bythe alternating pressure in the zone of the outlet from the central boreand the outlets of the oblique bores 4 are displaced into the range ofcompressive stresses.

In FIG. 1 this is achieved by the housing bore being stepped. The bore18 of larger diameter than the bore 2, is carried in so deeply that thevalve body 3 has the seating surface I9 projecting so far beyond thestep 20 formed at the junction of the two housing bores 2 and 18 thatafter mounting of the packing 16 against the annular surface 20, theouter cylindrical surface of the suction end of the valve body 3 isbrought over the predetermined length under the action of the constantdelivery pressure. By this means the stresses arising from thealternating pressures acting in the central bore '6 and the out;

lets from the oblique bores 4 lying in the same neighbourhood aredisplaced into the range of compressive stresses.

The arrangement illustrated in FIG. I has the disadvantage that thecylindrical bore of the valve housing 1 must have a shoulder to receivethe packing 16. FIG. 2 illustrates how this disadvantage can be removed.In this example the shoulder for receiving the packing 16 is provided onthe valve body 3 and the bore in the housing I can be made without astep. The effect of the action of the delivery pressure on the suctionvalve end of the valve body 3 obtained in this way is similarto thatobtained in the arrangement of FIG. 1.

It is however easily possible for both the bore in the valve housing 1and the cylindrical external surface of the valve body 3 to be madewithout steps. Such an embodiment is illustrated in FIG. 3. In this casea cylindrical intermediate sleeve 26 which has a through opening 26a forthe sucked in medium is inserted between the valve housing 1 and thevalve body 3. The packing ring 16 bears against the outer end surface ofthe intermediate sleeve 26.

The valve body 3, the intermediate ring 8 with inserted suction valvelift-limiting member 9, the delivery valve seat 12 and the deliveryvalve lift-limiting member 21 are centred and combined into a commoninsertable and removable unit by an external sleeve 22.

As shown by way of example in FIG. 1 the sleeve 22 for effecting thishas a shoulder 23 at the right hand end and an internal screw thread 24at the left hand end which is screwed on to corresponding externalthreads on the right hand end of the valve body 3. Obviously othersecuring means could be used on the valve body 3.

lclaim:

l. A combined suction and delivery valve for high pressure compressorsand pumps, comprising a housing 1 with a bore having a suction duct (s)and a delivery duct (x) leading thereto, a valve body 3 located withinsaid housing boreand having a central bore 6 and suction channels 4communicating with said suction duct, said suction channels extendingobliquely from the periphery of said valve body to a side face of saidvalve body forming a suction valve seating surface 19, an intermediatering 8 having a central bore 17 located adjacent the peripheral portionof said seating surface 19, a suction valve located coaxially withinsaid central bore 17 and having a central bore 10, said suction valvecomprising a coaxially located annular suction valve obturating member5, means biasing said suction valve obturating member onto said valveseating surface to block said suction channels and an annular valve liftlimiting member 9 cooperating with said obturating member, a deliveryvalve located adjacent said suction valve and said intermediate ringcomprising an annular valve seat member 12 having a central bore 11communicating with said delivery duct and a lift limiting member 21located coaxially with respect to said valve seat member 12, anobturating member 13 guided in said lift limiting member to obturatesaid central bore 11 of said valve seat member 12, means biassing saidobturating member 13 against said valve seat member 12, said centralbores 6, 10, 11 forming a unitary bore for communicating with theworking bore 27 of a piston, the fluid to be compressed enters saidhousing through said suction duct (s) and said oblique suction channels4 to fill said central bores 6, 10, 11 and is then delivered, during thedelivering stroke of said piston through said delivery valve and saiddelivery duct (x), said valve body (3) with said intermediate ring 8,said suction valve 9, 5 and said delivery valve 12, 13, 14 constitutinga unit which can be inserted in and removed from said housing as aWhole.

2. A valve according to claim 1 wherein said valve body, saidintermediate ring, said delivery valve seat member 12 and said deliveryvalve lift-limiting member 21 are held together by a sleeve fitting saidbore in said housing, said sleeve at one end having a shoulder engagingsaid delivery valve lift-limiting 21 member and at the other end isconnected to said valve body.

3. A valve according to claim 1 wherein said intermediate ring is madeof a material of higher modulus of elasticity and higher compressivestrength than the material of said valve body and said delivery valveseat member 12.

4. A valve according to claim 1 wherein a packing ring is arranged onthe periphery ofsaid unit.

5. A valve according to claim 4 wherein a shoulder is provided in saidbore in said housing against which said packing ring bears.

6. A valve according to claim 4 wherein a shoulder is provided on theperiphery of said valve body against which said packing ring bears.

7. A valve according to claim 4 wherein an intermediate sleeve isinserted between said housing and said valve body serving as an abutmentfor said packing ring.

